Special Notes (*):

Lenovo U31-70

Wireless needs linux >= 4.3 and latest linux-firmware, both packages are currently in testing. Copy one of the firmware blobs eeprom_ar6320_2p1_NFA345i.bin or eeprom_ar6320_2p1_NFA345i_highTX.bin from the windows driver to /usr/lib/firmware/ath10k/QCA6174/hw2.1/board-pci-168c:0041:17aa:3545.bin.

With packages linux 4.6.1-2 and linux-firmware 20160516.80d463b-1 being in stable, wireless works without any additional steps needed.

Lenovo B50-70

UEFI:

to be able to disable Secure Boot (necessary for dual boot, not needed for Linux only), you have to switch from "UEFI first" to "UEFI only" (or something like this) in UEFI setup menu; the Secure Boot option appears then on the Security tab

after UEFI update having Linux and Windows installed, the Linux bootloader ceased to be the default one, UEFI started to load Windows by default and it was impossible to select the Linux one in the UEFI boot menu and in the UEFI setup - reinstalling the bootloader helped; having no access to a boot media that supports UEFI, a solution might be also replacing the Windows EFI bootloader file with a Linux one temporalily, in order to be able to boot Linux from HDD

for the UEFI update, a Windows OS is needed

Touchpad:

Synaptics - works after installing Synaptics drivers from repo, possible to change behaviour (like reaction for double tap) according to your wish

Video:

in laptops with dual video card (Intel and ATI) - detects both, Intel is active as a default, not checked if it's possible at all to switch between them

Operation with a HDD caddy

When you install an SSD in the place of the plate HDD drive and you want to have your HDD still inside the laptop, it is possible to install it in the place of the optical drive in a special "HDD caddy". The optical drive is of 9 mm height, but a 9,5 mm caddy (ultra slim) fits in the slot. A caddy with a SATA interface is needed. It is difficult to separate the front bezel from the original optical drive (and opening its case does not help, but brings a danger of making a mess in the opening mechanism; the only option is just to pull the bezel using a bit of force, but you risk breaking the latches).

While the HDD installed instead of the optical drive operates flawlessly in Windows, it was not going to work out of the box in Linux, at least in one case. The kernel tries to establish a connection with the disk, but fails to do it (SATA link down entry in /var/log/messages). The solution is to force a 1.5 Gbps transfer speed (instead of 6 Gbps) by adding a libata.force= kernel parameter. See [1] for details.

Lenovo K450e

After installing Arch Linux and booting, a single beep may be heard. To disable this beep, press F1 during startup, then change Boot Priority to 'UEFI First', as well as enabling 'CSM'.

Lenovo ThinkPad T440p

ClickPad: the whole trackpad clicks, and disabling the trackpad using older versions of synclient makes the trackpoint essentially unusable. This has been resolved in newer versions of xf86-input-synaptics.

HDMI audio is the default audio output device. Consult the ALSA page for details on changing the default.

As the X100e/Mini10, it's possible to mute the headset and speaker outputs separately to the master. Muting the speaker output improves bass output on the headset port.

If the system fails to wake from sleep, it can lose sync with the internal audio card and speakers/headphones may fail to work. In this case, put the system to sleep, and wake it again and audio functionality should be restored.

The fingerprint sensor is a Validity VFS5011, which requires a patched fprintd and is apparently highly unreliable.

thinkpad_acpi:

To toggle Fn-Lock, press Fn + Esc, this will toggle the LED on the keyboard. While the Fn LED is on all Fn functionalities work as intended out of the box.

Controlling the 'glowing I' LED is apparently not possible.

fan control does not seem to work.

Graphics and Video:

With the integrated GPU, xrandr can crash while attaching or detaching displays connected via the dock.

The built-in miniDisplayPort will sometimes spew I²C issues into the kernel log.

The BIOS should not be upgraded past version 1.14, as newer BIOSes cause memory corruption when used with Bumblebee. See Bumblebee GitHub

Connectivity:

Bluetooth is extremely fragile. The controller works fine most of the time, but can cause the system to wedge totally on sleep/wake cycles, especially if a connection was active at sleep. Disable the controller using bluetoothctl before sleeping.

Lenovo S21e-20

Synaptics touchpad required 3 patches to linux:drivers/hid/hid-rmi.c on 2015-07-26 (bug report, kernel recipe patch). The current 4.3 kernel includes these patches. You will also need to install the xf86_64-input-synaptics package([2])

tpacpi-bat

There is an issue with tpacpi-bat not reporting the right value for the stop threshold. This seems to be related to a buggy BIOS and can not be fixed application wise.